Outpost
A strong square, usually for a knight, that is protected by a pawn and cannot easily be attacked by enemy pawns.
Knights on outposts, particularly in the center or near the opponent's king, are often extremely powerful because they cannot be dislodged without significant structural concessions from the defender.
Etymology
Outpost is a genuine military borrowing, attested from 1757 originally in George Washington's letters. The chess sense — a piece, usually a knight, planted deep in enemy territory on a square no enemy pawn can attack, supported from behind like a forward garrison — is inseparable from Aron Nimzowitsch, in whose My System the word occurs some fifty-seven times. Nimzowitsch claims the theory as his own and dates it: “I published the law of the establishment of outposts in open files about fourteen years ago in the Wiener Schachzeitung,” placing the original article around 1911. Mein System appeared in German 1925–27 and in English in 1929, translated by Philip Hereford. Notably, the word appears in none of the pre-Nimzowitsch English texts searched in this research (Philidor 1777 through Capablanca 1921), supporting Nimzowitsch as the term's popularizer in English chess writing.
First documented: 1911 — Nimzowitsch's article in Wiener Schachzeitung, as described in My System (English ed. 1929)
Translations
Translations for this term haven't been added yet.